Bug 2466785 (CVE-2026-43062)

Summary: CVE-2026-43062 kernel: Bluetooth: L2CAP: Fix type confusion in l2cap_ecred_reconf_rsp()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's Bluetooth L2CAP component. A type confusion vulnerability exists in the `l2cap_ecred_reconf_rsp()` function, where incoming data is incorrectly cast. This can lead to valid L2CAP_ECRED_RECONF_RSP packets being rejected and incorrect data being processed, potentially causing a denial of service or unexpected behavior.
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Description OSIDB Bzimport 2026-05-05 17:02:35 UTC 
In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: L2CAP: Fix type confusion in l2cap_ecred_reconf_rsp()

l2cap_ecred_reconf_rsp() casts the incoming data to struct
l2cap_ecred_conn_rsp (the ECRED *connection* response, 8 bytes with
result at offset 6) instead of struct l2cap_ecred_reconf_rsp (2 bytes
with result at offset 0).

This causes two problems:

 - The sizeof(*rsp) length check requires 8 bytes instead of the
   correct 2, so valid L2CAP_ECRED_RECONF_RSP packets are rejected
   with -EPROTO.

 - rsp->result reads from offset 6 instead of offset 0, returning
   wrong data when the packet is large enough to pass the check.

Fix by using the correct type.  Also pass the already byte-swapped
result variable to BT_DBG instead of the raw __le16 field.
Comment 1 Alexander B 2026-05-06 09:52:44 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050538-CVE-2026-43062-053e@gregkh/T